The cellular system was primarily designed to deliver voice and data services to the users. Users require real-time responses—that is, when a far end user calls a Wireless Terminal, they expect the Wireless Terminal to ring within seconds. The cellular system is designed to meet this need by having the Wireless Terminal look for pages frequently (once every second or so). Cellular networks send pages for specific Wireless Terminals in specific frames, and Wireless Terminals wake-up only during that specific frame to look for this page and sleep rest of the time. (A page is an indication from the cellular network to the Wireless Terminal that someone wants to communicate with it; A page is typically followed by the establishment of a communication session). The cellular network does require the Wireless Terminal to wakeup frequently, every second or so, in order to meet the real-time requirements of the user. This consumes substantial battery power at the Wireless Terminal. In today's cellular network, a typical Wireless Terminal in standby mode (that is when merely listening for pages and not having any data or voice communication sessions) depletes the battery within a few days to a couple of weeks depending on the particulars of the Wireless Terminal.
However, there are also a number of applications that can use the cellular network that do not require a real-time response; it is okay for the far end to reach the Wireless Terminals within minutes or hours rather than seconds (referred to hereafter as non-real-time communication). For example, a machine manufacturer may want to download new data into a machine in the field occasionally, where it is sufficient for this new data to reach the machine within an hour. Or as another example, a courier may want to periodically track the location of a piece of cargo which has a GPS location device and Wireless Terminal, etc. There is significant value in increasing the battery life of Wireless Terminals for such applications by leveraging the fact that this type of communication does not require a real-time response. But, requiring changes to existing cellular network paging methods only for these non-real-time applications is very expensive and impractical. There is significant value if paging methods could be devised which can substantially increase the battery life of Wireless Terminals without imposing changes on the existing cellular network